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Big Ip Local Traffic ManagerApplication · F5

CVE-2018-17539

HIGH · 7.5 CVSS v3.0 Published 2018-12-28
Fix available
A fix is available. Upgrade to after 13.1.1 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
The BGP daemon (bgpd) in all IP Infusion ZebOS versions to 7.10.6 and all OcNOS versions to 1.3.3.145 allow remote attackers to cause a denial of service attack via an autonomous system (AS) path containing 8 or more autonomous system number (ASN) elements.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

The BGP daemon (bgpd) in IP Infusion ZebOS (through 7.10.6) and OcNOS (through 1.3.3.145) contains a vulnerability in AS path attribute handling. When a remote BGP peer sends an AS path containing 8 or more ASN elements, it triggers a denial of service condition, likely due to missing bounds checking or improper input validation in the AS path parsing routine.

MitigationApply vendor patches for ZebOS and OcNOS. As a defensive measure, configure BGP peer filters to reject updates with AS paths exceeding a reasonable length threshold, and implement BGP route validation to limit accepted AS path lengths.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Big Ip Local Traffic ManagerApplication
Affected:>= 11.2.1, <= 11.6.3>= 12.1.0, <= 12.1.3>= 13.0.0, <= 13.1.1= 14.0.0
OcnosApplication
Affected:<= 1.3.3.145
ZebosApplication
Affected:<= 7.10.6

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify the BGP daemon software product and version
    Run 'show version' or check the system documentation to determine if the device runs IP Infusion ZebOS, OcNOS, or F5 Big-IP LTM. For F5 Big-IP, use 'tmsh show sys version' or check the GUI under System > Software Management > ISO Image.
    Affected if The device runs ZebOS <= 7.10.6, OcNOS <= 1.3.3.145, or F5 Big-IP LTM versions 11.2.1-11.6.3, 12.1.0-12.1.3, 13.0.0-13.1.1, or 14.0.0.
  2. Verify BGP is configured and active
    Check the BGP configuration using 'show ip bgp summary' (ZebOS/OcNOS) or 'tmsh show ltm virtual' and review BGP neighbor status. Use 'show running-config | include router bgp' to list active BGP instances.
    Affected if BGP is enabled and peers are configured. The vulnerability requires BGP to be running for a crafted AS path to be processed.
  3. Identify BGP peers and AS path configurations
    Run 'show ip bgp neighbors' (ZebOS/OcNOS) or check the BGP peer configuration in the F5 Big-IP device management. Look for configured AS path filters or AS path length limits.
    Affected if BGP peers exist. The vulnerability is triggered by receiving a BGP update with an AS path containing 8 or more ASN elements from a remote peer.
  4. Check for AS path length limits in BGP configuration
    Review BGP routing policies using 'show ip bgp policy' (ZebOS/OcNOS) or examine route maps and prefix lists in the BGP configuration. Look for 'as-path' match conditions or AS path length filters.
    Affected if No AS path length restrictions are configured. The advisory notes that configuring peer filters to reject AS paths exceeding a reasonable length can mitigate the issue.

A system is affected if it runs a vulnerable ZebOS, OcNOS, or F5 Big-IP LTM version AND has BGP enabled with peers, allowing remote BGP peers to send AS path attributes containing 8 or more ASN elements.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Upgrade available Upgrade to a release after 13.1.1
Interim mitigation

Apply vendor patches for ZebOS and OcNOS. As a defensive measure, configure BGP peer filters to reject updates with AS paths exceeding a reasonable length threshold, and implement BGP route validation to limit accepted AS path lengths.

Fix this in Big Ip Local Traffic Manager Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing4.0 h
  • Review / QA2.0 h
13.0 hours of engineering $2,280
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2018-17539 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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  • No spam, self-promotion, credentials, or personal data